What is the basic principle of a 3 phase transformer ?
Imagine a mains voltage wave. It has a frequ of 50Hz or 60Hz depending on where you live. Now imagine one single cycle starting at zero and looking like a sine wave, call it wave 1. Now imagine another sine wave that doesn’t start until it is 1/3 of the way through wave 1 ie it is offset, this is wave 2. Now imagine yet another sine wave that doesn’t start until it is 2/3 of the way through wave 1, this is wave 3. And that is what a three phase system is like. There are three wires in to the transformer and each one carries a voltage offset in time (or phase to be accurate) to the others. In fact a three phase transformer is like three separate transformers which have just been joined together at the earth terminal, so there are three inputs (one for each phase) and a single common connection. There is a cunning outcome of all this (or there would be no point in doing it). If you add up the total current in the common earth wire, then because off the offset in voltages resulting in som
